redux_form.jsx

// Reducer.js
const initialState = {
  user: {
    email: null,
    name: null,
  },
  myForm: { // define our form in advance
    input1: null,
    input2: null,
  },
}

const Reducer = (state = initialState, action) => {
  switch (action.type) {
    case 'UPDATE_FORM':
      return {
        ...state,
        [action.payload.form]: {
          ...state[action.payload.form],
          [action.payload.key]: action.payload.value,
        },
    default: return state
  }
}

export default Reducer


// Store.js
import { createStore, } from 'redux'
import Reducer from './Reducer'

const Store = createStore(Reducer)

export default Store


// Actions.js
export const updateForm = payload => ({
  type: 'UPDATE_FORM',
  payload,
})


// App.js
import React from 'react'
import { Provider, } from 'react-redux'
import Store from '../redux/Store'

import AppWrapper from './AppWrapper'

export const App = props =>
  <Provider store={Store}>
    <AppWrapper />
  </Provider>

export default App


// AppWrapper.js
import React from 'react'
import { connect, } from 'react-redux'
import * as Actions from '../redux/Actions'

const update = (params, props) => props.updateForm(params)

export const AppWrapper = props =>
  <div>
    <input 
      value={props.myForm.input1}
      onChange={e => update({
        form: 'myForm',
        key: 'input1',
        value: e.target.value,
      }, props)}
      type={'text'} />
    <input 
      value={props.myForm.input2}
      onChange={e => update({
        form: 'myForm',
        key: 'input2',
        value: e.target.value,
      }, props)}
      type={'text'} />
  </div>

const mapStateToProps = state => ({
  myForm: state.myForm,
})

const mapDispatchToProps = dispatch => ({
  updateForm: params => dispatch(Actions.updateForm(params)),
})

export default connect(mapStateToProps, mapDispatchToProps)(AppWrapper)